Basing rights on species is arbitrary. It is no more rational than basing
rights on the pigmentation of skin or on gender, which are also determined
genetically.

I look at the term "species", as one arbitrarily given for the
sake of convenience to a set of individuals closely resembling each other...

Charles DarwinThe Origin of Species

Inalienable Rights

As a society, we recognize basic rights of humans to their lives and bodies.
We consider these rights "inalienable", meaning that no one can take
them away.

Humans are granted rights to their lives because most have a strong desire
to avoid death and suffer fear when their lives are threatened. Humans are
granted control over their own bodies because they suffer pain when their
bodies are mutilated, and boredom and frustration when caged for long periods
of time. Since we, as a society, understand how horrible these sorts of
sufferings are, we try to protect humans from those who might kill, mutilate,
or cage them, regardless of the benefits to others that such sufferings might
bring.

Animals whom we have made our slaves, we do not like to consider our
equals.

Charles DarwinMetaphysics, Materialism, and the Evolution of Mind

Based on common physiology and behavior, it is safe to say that vertebrate
animals suffer fear when their lives are threatened, pain when their bodies are
mutilated, and boredom and frustration when caged for long periods of time.

In speaking about whether animals should be granted rights, Jeremy Bentham
(Oxford University Professor of Jurisprudence) said, "The question is not,
Can they reason? nor, Can they talk? But rather, Can they suffer?" (An
Introduction to the Principles of Morals & Legislation, 1789) For those
who can suffer, the degree of suffering, not the species of the sufferer, is
what should count. Similarly, if an individual desires to live, then its life
should be respected.

Animals show they value their lives and freedom by their struggles against
being caged and killed. The act of depriving them of life or freedom harms them
in many of the same ways a human is harmed when deprived of life or freedom.

Since animals can feel pain and desire to live, should they not be granted
basic rights to their lives and bodies? As individuals capable of acting
morally, how can we justify their continued exploitation and slaughter?